Remote control system



Paen[ed Aug. 8, 933

UNITED STATES PATENT OFFICE 'I1isivention relates to inlproved a'nd si1 )1- ned neans for the a!npli1...cti0n for Snlll alternating curent in1pulses. It is especially adapted for reTlote control purpose8 and fol' all such cases where the indicating nlean8 is not a(ble to trans :1it enough tol'que to eect the desiTed l'e Sults, 8S for instance, the indicgtion of a' denc8te measuring instrument has l;o be used to contr01 pparatus vvhich i itSel needs consider- 8ble power for opea,tion.

'I}1S invention h s 8peci l application for a'll such cases Where the ut10st Silplicity and efnciency is required and where n0 Supply of direct cur ent is readily available for the 0peration of the ainpiner proper. v-'hile direct curent ny be procured for such operEtions fro!n an alte1' n ting source by the use of ectifying devices' Such devices tend to c0plicate the a'1 )line1' and its co!nponent parts. They also Inake Ino!e parts and tubes necesSay and Tepresent in thenselves a possib1e source of error End failure' I therefore have arranged nly invention so that there is no necessity for ar Sepaate direct current supply no nlatter Whether procured froln a direct current source or by recticati( n thereby nlaking the whole circuit aS Sinple as possible.

The Znain application oftllis invention relates especi ny t0 the a1nplincation of altenating current iInpulses true to power factor and pr0 portional to an1plitude provided that the indicat ing ixT1pulse has the Sanle frequency as the alternating current supply line. changes of the phase of the input with relation to the phase of the alternating current line will therefore appear vvith exactly the 'sanle povver fact0' across the output of the a!np1i1ier but with largely aInplied amplitude Therefore a change of the phase angle of the input will be duplicated without any change in the output circuit while a change of amplitude nf the input impulse will appear am plined in the output circuit Referring to the drawing in which tw0 preferred forlns of Iny invention are shown;

Fig. 1 Shows the genera1 Scheme of the amp1iner on a single phase alternating current line Fig. 2 Shows a. special app1ication of the same circuit on a 3-phase line fo1' the control of a 3-phase aternating current Inotor.

Referring to Fig. 1, the alternating current supply line is represented by 1 and 2 and the input inlpulse nlay be introduced by a' s!nal transfor!ne1 coil 3 Which Inay be connected to the pivot of an electric rneasuring instrument (not showp) or other sensitive indicato1 and connected to the alternating ourrent 1ine in some manner which for the purpose of this in venti011 is i!nmaterial. "The coil 4 represents the receiving end qf the amplmer n Which the impulse from coil 3 induces a corresponding hnpulSe. T'he arrovv through the tvvo coils indicates that their relative position cal be cha1ged so a,s to eect a change of phase angle. It is obvious that if coi 3 is turned 180' in a' )lane vertical to the plane of the drWing, the phase in coll 'is ieversed. It is il1te'il vit! l'e spect to the purpose 0f this invention Whethe the indicating impulse s generated by inductive, cap citive, other 1e3!s vvell known to the art. ()ne end of the coil is connected to the gri(i 5 0f the three elen1ent v cuu!n tube 6. ';'his vacuun1 tube has its nlEnlent heted by the ce! tel tapped vvinding 7 0f the tran8forner 8 hv ing its prima y 9 connected to the alternating current line 1, 2. This same transformer 9 my also supply the heting current for the vcuum tubes 10 and 11 by !le91s of the cente' ta'pped winding 12. It furthermore preferably Supphes the plate potentials for all three tubes by al speci9l arrangement, in which the high potential center t pped winding 13 generates the plate potential for tubes 10 and 11, the plate current of vvhich creates a voltage drop across resistor 1, this voltage drop being Sed pamy to sup ply the plate potentia1 fol` tube 6.

'I'he i!pulse i duced in coil vvill create an tube 6. By the well known action of a three elenlent vacuun tube t1is `glte111a'ti1g current p0tenial vi1l create a correspondi1g change in the plate curTe I t of tube 6, Which in turn is put through the prnary winding 15 0f tr nsformer 16. In the ec0ndary winding 17 of this transf0mer therefore, Will be induded an alternating current potentia1 in proportion to the change of cuTrent in the prinary vvinding potential is again applied to the grids 18 and 19 0f tubes 10 and 11. The plates of these two tubes aresupplied with potential fro!n the winding 13 in such a' vvay that one end of the vvinding is connected to tube 10 and' the other end to tube 1 1- The coils 20 and 21 0f the output' transforIner 22 aTe each connected in series vvith the plte of one of each of the tubes so that the plate currents of the tubes have t0 p9ass through sarid coils.

It is v"ell known that a three elenent vacuun1 tube vvill only show a large plate current if the plate is positive enough vvith respect b the fllal- Inent In Iny anlplifier the plates of tubes 10 and ll are supplied vvith alternating current 110 stages, and said resistor furnishing a feed-back 10. In an impl1se detecting and amphfying system of electron tubes, an alternating cunent supply, an input device, a pail` of power ampli 1'ying tubes, 9 ttansfornler excited from Said supply having a plurality of secondary Windings for supplyi11g all plate potentials and heating currents to sarid tubes, including a high voltarge center tapped secondary having opposite ends) thereof connected to the plates of the tubes so as to cause said tubes to act sixnu1taneousl as amplifying and rectifying tubes, a Tesistor connected between Said center tap nd the electrical center of one of said seconda$y heater windings supplying the maments of S9id tubes s0 that the plate currents of both tubes now through said resistor always in the same direction.

11 In a nnultistage electron tube ower amplifying system an elec#ron tube an1 liner stage, 9 second anlplijer stage having two tubes, an alter118ting current supply trnsformer for the plates there0f, an output transfornler having one primar winding in circuit with the plate of one tube of said second stage and Said supply and a.nother prinlary winding in circuit vvith the plate of the 0ther tube and said supply, the direction of the windings and the plate currents being such aS to nlagnetize the core of said transformer unidjrectionlly ar tapped re- Sist01 through Which both plate currents 9Te flowing un dircipna'ny, the v0ltge drop along this Tesistor Supplying direct cunent potentials to all stages, Said resistor thereby furnishing a feed back connection to s8id Tst mentioned electron tube.

12. A motor contr01 electronic circuit 01 g0v erning the speed) and direction of a power !!10 tor col!1prising, in cornbination with the lnotor, an alternating current supply and a tW0prt controner having a' Teversible phase output enerized ,from said Supply, a secondary powered from said supply. a pai1` of electron tubes hv ing thei1' grids connected par9llel t0 said output and thei1` plates connected t0 0pposite ends of said sec0nda y means for deriving gridbiasing voltage for said tubes from the combined direct co!n onents of thei1' plate currents, and means for separting from the Said p19te currents the combined a1ternating ;com onents thereof to drive said motor.

13. A motor contr01 electronic cifcuit for governing the Speed and direction of a three phase motor conl rising, in combination with the motor, 9' three phatse supply and a tW0-part con troller having a' reversible phEse output energized fronl a hase of said su ply, 9`secondar owered frotn the same hase of su l a air of electron tubes having their gTids connected in arallel to said output and their lates connected to opposite ends of said Secondary, means 135 for deriving grid-biasing voltage fol said tubes from the combined direct components of their ate currents, means for separating from the said plate currents the combined alternating c0nponents thereof, and Ineans for splitting Said output to drive said motor therefrom as combined with the third Wire of said supply.

BRUNO A. WITTKUHNS. 

